I did 3 Experiments and got 3 rate as the following:

Question

Exp1: (S2O8)2-:0.05M; I-:0.05M rate:1.7x10^-5 M/s

Exp2: (S2O8)2-:0.10M; I-:0.05M rate:3.4x10^-5 M/s

Exp3:(S2O8)2-:0.05M; I-:0.10M rate:3.6x10^-5 M/s

what effect does doubling [(S208)2-] have on the rate? By what factor does the rate increase?

what effect does doubling [I-] have on the rate? By what factor does the rate increase?

How do I calculate x, y for the rate law: Rate=K[(S208)2-]^x times [I-]^y? Do I substitute the value of[(S208)2-]and [I-] from each Exp?

How do I calculate the value of the rate constant K for each Exp and the average value?